/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/* $Id: CrossReferenceTable.java 1305467 2012-03-26 17:39:20Z vhennebert $ */
package org.apache.fop.pdf.xref;
import java.io.IOException;
import java.io.OutputStream;
import java.util.List;
import org.apache.fop.pdf.PDFDictionary;
import org.apache.fop.pdf.PDFDocument;
/**
* A cross-reference table, as described in Section 3.4.3 of the PDF 1.5 Reference.
*/
public class CrossReferenceTable extends CrossReferenceObject {
private final List<Long> objectReferences;
private final StringBuilder pdf = new StringBuilder(256);
public CrossReferenceTable(TrailerDictionary trailerDictionary, long startxref,
List<Long> location) {
super(trailerDictionary, startxref);
this.objectReferences = location;
}
public void output(OutputStream stream) throws IOException {
outputXref();
writeTrailer(stream);
}
private void outputXref() throws IOException {
pdf.append("xref\n0 ");
pdf.append(objectReferences.size() + 1);
pdf.append("\n0000000000 65535 f \n");
for (Long objectReference : objectReferences) {
final String padding = "0000000000";
String s = String.valueOf(objectReference);
if (s.length() > 10) {
throw new IOException("PDF file too large."
+ " PDF 1.4 cannot grow beyond approx. 9.3GB.");
}
String loc = padding.substring(s.length()) + s;
pdf.append(loc).append(" 00000 n \n");
}
}
private void writeTrailer(OutputStream stream) throws IOException {
pdf.append("trailer\n");
stream.write(PDFDocument.encode(pdf.toString()));
PDFDictionary dictionary = trailerDictionary.getDictionary();
dictionary.put("/Size", objectReferences.size() + 1);
dictionary.output(stream);
}
}